Research On Preparation Of Graphene Transparent Conductive Films

Graphene, a two-dimensional honeycomb crystal structure, holds promise tobecome a transparent conductive electrode, replacing ITO, due to its extraordinaryelectrical, optical, thermal, and mechanical properties. The oxidation reductionmethod can realize the mass preparation introducing a large number of oxygenfunctional groups in the process. The traditional chemical reduction or thermalreduction is hard to realize the recovery of carbon structure of graphene oxide （GO）.Hence, we designed to reduce GO with HI combined with1100℃high temperatureheat treatment to effectively eliminate surface oxygen functional groups to obtain highconductive graphene film.Primarily, this paper produced graphene flakes, with less defects and larger size,through gentle heating and ultrasonic treatment. GO sheets with thickness of0.8nmwere observed with lateral dimensions of several micrometers for a fully exfoliatedGO sheet through the atomic force microscope. Fourier transformation infraredspectra （FT-IR）, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）and Raman curves demonstrated that GO was a layered material bearing oxygenfunctional groups on its basal planes, destroying its neat structure to some extent.Scanning electron microscope （SEM） and transmission electron microscope （TEM）indicated wrinkled GO contains a certain regularity.We prepared a series of graphene films with different transmittance throughvacuum filtration, transferred them to the surface of guartz glasses and then handledthe GO films with1100℃high temperature （RGO1100℃） treatment or HI combinedwith1100℃high temperature (RGO_HI+1100℃) heat treatment to prepare reducedgraphene oxide （RGO） films. Ultraviolet absorption spectrum, Raman spectrum, XRD,XPS indicated RGO1100℃possessed smaller layer space, larger C/O ratio and I2D/ID+G.,demonstrating RGO_HI+1100℃possessed better surface structure. Film performance testshows that compared to RGO1100℃films, RGO_HI+1100℃films have higher conductivity.The transparent conductive films made from RGO_HI+1100℃show a sheet resistance2400Ω/sq at a transmittance of72%, and films made from RGO1100℃show a sheetresistance3600Ω/sq at the same transmittance. This is because the RGO_HI+1100℃films posess higher reduction degree and lower node resistance, further supporting thestructure characterization results.